Added forgotten Upsampling function

Signed-off-by: Nicola Vigano <nicola.vigano@esrf.fr>

zUtil_Maths/gtMathsUpsampleVolume.m

+function vol = gtMathsUpsampleVolume(vol, scale)
+% FUNCTION vol = gtMathsUpsampleVolume(vol, scale)
+
+    if (iscell(vol))
+        for ii = 1:numel(vol)
+            vol{ii} = gtMathsUpsampleVolume(vol{ii}, scale);
+        end
+    else
+        vol = upsample(vol, scale);
+    end
+end
+
+function vol = upsample(vol, scale)
+    vol_in_size = size(vol);
+    for ii_dim = numel(vol_in_size):-1:1
+        indx{ii_dim} = 1:vol_in_size(ii_dim);
+        indx{ii_dim} = indx{ii_dim}(ones(scale, 1), :);
+        indx{ii_dim} = reshape(indx{ii_dim}, [], 1);
+    end
+    vol = vol(indx{:});
+end